Liquid heat exchanger



n April 18, 1967 M. R. ESTABROOK 3,314,474

LIQUID HEAT EXCHANGER Filed March 9, 1965 5` Sheets-sheet 1 Il I f I l I,| I I I I I I l l I I I I I I i I g l I :15; 4f), e i l` I I g 1. /f g li l I I l I I l l I I v l u I l *Y I I I I I `l J CATTOnloEy/ APril 18, 1967 M. R. EsTABRoOK 3,314,474

LIQUID HEAT EXCHANGER Filed March 9, 1965 5 sheets-sheet 2 @v/o1' @mark Q JLEZDmO/L April 18, 1967 M. R. ESTABROOK v 3,314,474

LIQUID HEAT EXCHANGER Filed March 9, 1965 5 Sheets-Sheet .'5

United States Patent O "a 3,314,474 LIQUID HEAT EXCHANGER lark R. Estabrook, Rockford, Ill., assignor to llames Drill Co., Rockford, Ill., a corporation of Illinois Filed Mar. 9, 1965, Ser. No. 438,326 Claims. (Cl. 165-76) This invention relates to exchangers for changing the temperature of a moving stream of liquid and has more particular reference to exchangers in which the path of liquid flow in service use is likely to be blocked by the laccumulation of solids in the liquid being treated.

The primary object is to provide `a heat exchanger of the above character and of a novel construction which facilitates quick and easy cleaning and reconditioning after clogging under abnormal conditions encountered in service use.

Another object is to construct the exchanging elements for convenient washing and cleaning by the forcing of liquid therethrough.

A further object is to provide a heat exchanger having a coil through which the exchanging liquid flows mounted in a casing defining the treating chamber and adapted for removal to facilitate easy cleaning.

A related object is to provide a heat exchanger which not only is adapted for removal for thorough cleaning but which also may be washed and cleaned to eliminate conditions of minor clogging without removal `and while still in place.

Still another object is to provide a novelly arranged pumping and thermostatically controlled system for an easily cleanable heat exchanger of the above character.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which FIGURE 1 is a fragmentary elevational view of a combined filter and cooler embodying the novel features of the present invention with the housing broken away and shown in section.

FIG. 2 is a -pa-rt of FIG. 1 with the exchanger partially removed.

FIG. 3 is an enlarged fragmentary section taken on the line 3-3 of FIG. 5 with the pump against the frame.

FIG. 4 is a fragmentary perspective view of the heat exchanger with the top wall partly broken away.

FIG. 5 is a fragmentary horizontal section taken on the line 5-5 of FIG. 1 with the pump separated from the frame.

The improved heat exchanger in the form shown for purposes of illustration and indicated generally at is especially adapted for cooling liquid such as machine tool coolant to a predetermined temperature after the same has passed through a traveling filter web 11 in an automatic filter 12. The exchanger is disposed in the lower portion of an upright box-like housing 13 which supports the casing 14 of the filter above the exchanger and also supports ra power driven refrigeration unit 15 for cooling the refrigerant used in the exchanger.

When the filter is, for example, of the type shown in Patent 2,720,973, dirty coolant delivered to Van inlet 16 flows through the trough 17 of a magnetic separator and overflows at 18 into a body 19 conned above the filter web 11. The latter comprises a wide sheet of conventional filter paper and is supported and advanced intermittently by an endless apertured conveyor 21 by which the web and the filtered-out solids are carried out of the housing and discharged at 22.

The bottom of the filter casing 14 is open and the filtrate gravitating through the filter web falls onto the wall 23 of a shallow horizontal casing 24 in which is 3,314,474 Patented Apr. 18, 1967 ICC mounted a coil 20 through which refrigerated liquid is circulated. The casing wall 23 is a relatively fiat plate somewhat wider and longer than the effective area of the filter web and is disposed a short distance below the filter outlet. The bottom wall 25 of the casing rests on laterally spaced horizontal cross-rails 26 supported by posts 27 a short distance above the bottom 28 of the housing 13 which is supported on legs 29. Different areas of the bottom converge downwardly toward one or more drain outlets which are normally closed by removable plugs 31.

The top and bottom walls of the casing 24 Iare connected by spanning vertical side walls 32 and cooperate with the latter to define a shallow chamber 33 of rectangular shape having an inlet 34 across one end which is spaced from the opposed vertical wall 35 of the housing 13. The outlet at the other end of the casing extends through the opposite housing wall 37. Liquid entering the inlet and drawn through the casing flows over and comes in contact with the surfaces of a multiplicity of parallel portions of the coil 20 having fins 38 thereon closely spaced along the lengths of the coils between the side plates 32. These lengths are connected in series by bends 39 which are disposed outside of the walls 32 and within chambers which are defined by edge portions of the top and bottom casing walls, outer vertical side walls 41 and upstanding plates 42 closing the chambers at opposite ends of the inlet 34. The series connected coils terminate at inlet and outlet fittings 43 disposed outside of the housing and connected to flexible conduits 44 by which refrigerant cooled in the condenser 45 of the refrigerating unit 15 is forced through the exchanger during operation of a motor 46 which drives the compressor of the unit.

The large surface area of the coils and fins provides for rapid cooling of the filtrate. The efficiency of the exchanger is further increased by maintaining large areas of one or both of the casing walls 23 and 25 in contact with bodies of the filtrate before entering the casing inlet 34. One of these bodies is the liquid accumulating in the One of these bodies is the liquid accumulating in the bottom of the housing 13 when the drain plugs 31 are in place. By providing upstanding dams around the entire periphery of the top wall 23, a shallow body of the filtrate is retained on this wall in heat exchanging relation with the fins by virtue of their contact with the casing walls. The dams along the inlet edge of the wall are formed by an upstanding plate 47, along the ends by extensions of the plates 41, and at the outlet edge by an upwardly inclined portion 48 of the wall. The filtrate overflowing the shallow tank thus formed enters the inlet 34 of the exchanger casing and is induced to flow through the latter by a pump 49 which is driven continuously by a motor 51 when the combined filtering and cooling assembly is in operation.

In operation of a filter utilizing a traveling disposable web, it sometimes happens that the web breaks or. runs out resulting in the delivery of solids into the exchanger casing in amounts which are likely to -be caught between the closely spaced fins 38 thus causing clogging of the chamber 33. The present invention aims to facilitate quick and convenient cleaning of the exchanger to relieve such clogging mounting the casing-coil assembly in the housing 13 and coupling the same to the pump in a novel manner which permits a cleaning liquid to be flushed through the casing without removal thereof from the housing to relieve minor conditions of clogging or alternatively to remove the exchanger as a unit and permit more thorough cleaning in the case of more severe clogging of the exchange elements. To these ends, the casing 52 of the pump is coupled removably to a frame 53 v 3 which is disposed externally of the housing Wall 37 enclosing a hole 54 therthrough large enough to permit Withdrawal of the exchanger unit when the outlet end of thel atter is clamped to the frame.

The frame 53 is generally rectangular and clamped by screws S to a flange 56 which defines the housing opening S4. The terminal ends of the refrigerant coils extend through holes in and are clamped to the frame. To couple the outlet end of the casing 24 to the frame, the upper and lower walls are formed with outturned flanges 57 abutting against and secured by bolts 57a to the back of the frame., A flange 58 defiining the intake of the pump 49 is clamped by screws 59 against a flange 61 defining an opening 62 at the center of the frame communicating with the pump inlet. When the screws 59 are removed Ifrom the flange, it will .be apparent that the pump may be separated from the frame 53 as shown in FIGS. 2 and 5 thus exposing the frame opening 62 through which cleaning liquid may be forced under pressure through the casing 24 and out of the normal inlet 34 into the housing 13. By removing the plugs 31, the lower end of the housing 13 may be drained and the draining liquid along with the solids washed out of the exchanger casing may be carried out of the housing. Such separation of the pump from the housing is made possible by delivering the cooled filtrate to the desired point of use through piping which includes a flexible hose 63 coupled to the pump outlet 64.

When the clogging of the exchanger is sufficiently tight 'to preclude effective cleaning in the manner above described, the entire exchanger assembly may be withdrawn as a unit from the housing 13 as shown in FIG. 2. This is accomplished by removing the screws 59 and separating the pump from the frame 53. Then the screws 55 are removed to release the frame 53 and permit the latter with the exchanger casing attached to be slid out of the housing 13 along the rails 26 and withdrawn through the hole 54 as permitted by flexing of the refrigerant conduits 44. Fluid may then be forced through the casing 24 is either direction thus insuring effective cleaning of the casing and all of the spaces between the fins 38 and around the lengths of the coil 2u. For further cleaning, the top wall 23 can be taken off by removing the bolts 57a. After such cleaning and reassembly, the exchange 'unit is inserted through the hole 54 and slid inwardly along the rails 26 between the guide flangesr26a thereon. The frame is then reclamped to the housing wall 37 after which the pump is reconnected to the frame.

Location of the inlet 34 of the exchanger casing within the housing 13 and connection of the pump to the casing outlet is advantageous not only in facilitating cleaning in the ways above described but also in enabling the operation of the exchanger to be controlled automatically and the temperature of the treated filtrate to be maintained substantially constant. For this purpose, the operation of the refrigeration unit is controlled in response to changes in the temperature of the liquid with the pump casing 52 preferably close to the outer end of the inlet dened fby the flange 58. The temperature sensor may, as shown, take the form of a bulb 65 (FIGS. 2 and 3) disposed Within a tube 66 projecting through and sealed in the pump casing 52 close to the inlet iiange 58. Pressure changes in the bulb resulting from expansion and contraction of the liquid in the bulb are communicated through a flexible capillary tube 67 to a sutiable :switch mechanism 67 (FIG. 1) by which the motor 46 'of the refrigeration unit 15 is stopped and started as the temperature of the liquid being withdrawn and confined within the exchanger casing respectively rises above and falls below the sensing range of the bulb, The latter, it will be observed, is disposed close enough to the exchanger to operate with the desired accuracy in sensing decreases .in the liquid temperature within the exchanger when no liquid is being circulated therethrough. lf desired, the tube 66 may be constructed as shown in FIG. 3 to permit removal of the bulb as shown in FIG. 2 as a preliminary to removing the exchanger unit from the housing 13.

l claim as my invention:

1. In a liquid heat exchanger, the combination of, a housing having an inlet for receiving liquid Whose ternperature is to be changed and having a side -wall for-med with an opening therethrough, a frame disposed against the exterior of said side wall around said opening to close the latter and being formed with an opening smaller than said side Wall opening and defining an outlet, a casing disposed within said housing below said inlet and having an outlet end secured to the inside of said frame and communicating with said frame outlet, the opposite end of said casing constituting an inlet opening within said housing, a heat exchanger coil disposed within said casing and having inlet and outlet tubes extending through and supported by said frame, means communicating with said tubes for circulating heat exchanging fluid through said coil, means for directing liquid delivered into said housing to said casing inlet for dow through the casing, a pump disposed externally of said housing and against the outside of' said frame and having an intake communicating with said frame outlet to draw the liquid through said casing and out through said casing outlet and said frame outlet, first means detachably clamping said frame against the exterior of said housing, said frame, casing, coil and pump being lfastened together as a unitary as'- sembly movable upon release of said clamping means for removal from said housing with said casing passing through said opening in said housing side wall, and second means detachably clamping said pump to said frame to enable exposure of said frame outlet upon detachment and separation of said pump from said iframe whereby cleaning fluid ymay flow reversely through said frame outlet, into said casing through said casing outlet, and into said housing through said casing inlet.

2. A heat exchanger as defined in claim- 1 including iiexible conduits leading to said inlet and outlet tubes of said coil and communicating with said circulating means so as to enable removal of said unitary assembly from said housing upon release of said -first clamping means and detachment of said frame from said housing side wall.

3. A heat exchanger as defined in claim 2 in which, said pump includes an outlet, and a flexible conduit coupled to said pump outlet so as to permit separation olf the pump from the frame after release of said second clam-ping means. Y

4. A heat exchanger as defined in claim 1 in which said pump includes a casing, an elongated tube having a closed end disposed within said pump casing adjacent said pump intake and having an open end disposed outside of said pump casing, and a thermostatic element disposed within said tube and controlling the operation of saidV circulating means in response to changes in the temperature of the liquid drawn into said intake.

5. A heat exchanger asdefinedin claim- 1 including a drain chamber in said housing below said casing, and means by which said chamber may be drained of said cleaning liquid.

References Cited by the Examiner UNITED STATES PATENTS 2,110,024 3/1938 Miller 165-75 2,282,373 5/1942 Minkler et al. l65-48 2,994,514 6/1961 BrOWn 165--107 ROBERT A. OLEA-RY, Primary Examiner.

CHARLES SUKALO, Examiner. 

1. IN A LIQUID HEAT EXCHANGER, THE COMBINATION OF, A HOUSING HAVING AN INLET FOR RECEIVING LIQUID WHOSE TEMPERATURE IS TO BE CHANGED AND HAVING A SIDE WALL FORMED WITH AN OPENING THERETHROUGH, A FRAME DISPOSED AGAINST THE EXTERIOR OF SAID SIDE WALL AROUND SAID OPENING TO CLOSE THE LATTER AND BEING FORMED WITH AN OPENING SMALLER THAN SAID SIDE WALL OPENING AND DEFINING AN OUTLET, A CASING DISPOSED WITHIN SAID HOUSING BELOW SAID INLET AND HAVING AN OUTLET END SECURED TO THE INSIDE OF SAID FRAME AND COMMUNICATING WITH SAID FRAME OUTLET, THE OPPOSITE END OF SAID CASING CONSTITUTING AN INLET OPENING WITHIN SAID HOUSING, A HEAT EXCHANGER COIL DISPOSED WITHIN SAID CASING AND HAVING INLET AND OUTLET TUBES EXTENDING THROUGH AND SUPPORTED BY SAID FRAME, MEANS COMMUNICATING WITH SAID TUBES FOR CIRCULATING HEAT EXCHANGING FLUID THROUGH SAID COIL, MEANS FOR DIRECTING LIQUID DELIVERED INTO SAID HOUSING TO SAID CASING INLET FOR FLOW THROUGH THE CASING, A PUMP DISPOSED EXTERNALLY OF SAID HOUSING AND AGAINST THE OUTSIDE OF SAID FRAME AND HAVING AN INTAKE COMMUNICATING WITH SAID FRAME OUTLET TO DRAW THE LIQUID THROUGH SAID CASING AND OUT THROUGH SAID CASING OUTLET AND SAID FRAME OUTLET, FIRST MEANS DETACHABLY CLAMPING SAID FRAME AGAINST THE EXTERIOR OF SAID HOUSING, SAID FRAME, CASING, COIL AND PUMP BEING FASTENED TOGETHER AS A UNITARY ASSEMBLY MOVABLE UPON RELEASE OF SAID CLAMPING MEANS FOR REMOVAL FROM SAID HOUSING WITH SAID CASING PASSING THROUGH SAID OPENING IN SAID HOUSING SIDE WALL, AND SECOND MEANS DETACHABLY CLAMPING SAID PUMP TO SAID FRAME TO ENABLE EXPOSURE OF SAID FRAME OUTLET UPON DETACHMENT AND SEPARATION OF SAID PUMP FROM SAID FRAME WHEREBY CLEANING FLUID MAY FLOW REVERSELY THROUGH SAID FRAME OUTLET, INTO SAID CASING THROUGH SAID CASING OUTLET, AND INTO SAID HOUSING THROUGH SAID CASING INLET. 